Immune System - Infectious Disease + Antibiotic Flashcards
Key terms
Pathogenic: An organism that causes a disease, damaging its host.
Infectious: A disease that may be passed or transmitted from one individual to another.
Carrier: A person who shows no symptoms when infected by the disease organism but can pass the disease to another individual.
Disease reservoir: Where a pathogen is normally found. This may be in humans or another animal and may be a source of infection.
Endemic: A disease that is always present in an area, but at low levels or stable
Epidemic: A significant increase in the usual number of cases of a disease,then fall
Pandemic: An epidemic occurring worldwide or in multiple countries, usually affecting a large number of people + cross continent
Vaccine: Uses non-pathogenic forms, products or antigens of microorganisms to stimulate an immune response which confers protection against subsequent infection.
Antibiotic: Substances produced by microorganisms that affect the growth of other microorganisms.
Antibiotic resistance: Where a microorganism, which should be affected by an antibiotic, is no longer susceptible to it.
Vector: A living organism which transfers a disease from one individual to another.
Toxin: Is a chemical produced by a microorganism which causes damage to its host.
Antigenic types/serotypes: Organisms with the same or very similar antigens on the surface. Such types are sub-groups or strains of a microbial species which may be used to trace infections. They are usually identified by using antibodies.
Antigen - spike protein in surface of membrane for identification + enter host
Classification of bacteria
Shape
-Coccus, spirillum (spiral helix), bacillus
Gram + or -
Microflora
Human body host to many bacteria
-symbiotic relationship, bacteria also assist body
-aid digestion, produce vitamin K etc
-if get to other part of other = problems
Types of infection disease
Gonorrhoea
-sexually transmitted via sex - bacteria gram -
-cause discharge by body mucus to flush it out
Cholera (Vibrio cholerae)
-by contaminated water
-affect gut lining increase activity CFTR channel = diarrhoea + lose many ions and water
-treated with antibiotics + electrolytes supplement + water
Influenza
-virus spread by droplet
-affect respiratory tract = sore throat
-no curable but vaccine often given since mutate
Malaria (plasmodium)
-spread by mosquitoes bite
-grow in blood cell and burst to spread more
-no vaccine different strand, mostly kill vector
-fish to eat larvae, insecticides
How to recognise virus + why virus so hard to treat
Recognise by spike protein (glycoprotein) on surface
Different to treat -
Not much function to interrupt (metabolism)
Mutate quick as only few gene
Classification of antibiotics
Extracted from micro-organism to kill of competition - purified
Board spectrum - effective against great range of bacteria (Tetracycline)
Narrow spectrum - effective against tighter range of bacteria (penicillin gram + or -)
Bacteriostatic - inhibit bacterial replication/growth - not killed (tetracycline)
Bactericidal - kill bacteria (penicillin)
How to assess effectiveness of antibiotic
Grow bacteria on petri
Add antibiotic
Larger clear zone where antibiotic placed = more effective
How does penicillin + tetracycline work
Penicillin
-disrupt murine cell wall
-inhibit enzyme responsible bonding murine together
-vulnerable to osmotic pressure = lysis
Tetracycline
-competitively bind to bacteria ribosome
-prevent translation of essential protein for binary fission
How does bacteria develop antibiotic resistance
Overuse of bacteria
-natural selection - does with resistance to antibiotics live and reproduce quickly due to low competition - pass resistance to next generation
Transfer of plasmids
-transformation: when bacteria die scattered plasmid collect by other bacteria
-conjugation: pili bind to transfer plasmids
-transduction: bacteriophage (virus that infect bacteria) act as vector to pass plasmids
